Method of filling a space under a structural element and structure therefor

ABSTRACT

In a known method of filling a space under a structural element with sand, sand and water are supplied into said space through a suspension conduit communicating with a suction dredging installation, rolling on and guided by said structural element, extending above the water level and sucking sand from barges. This suction dredging installation obstructs the shipping and cannot be used at bad weather conditions and/or great depth. For avoiding the above disadvantages the invention provides a method in which the suspension is supplied through a suspension conduit fixed to the structural element, and extending from a junction side of said structural element.

United States Patent Griffioen et al.

gekamp; Jorn Yding Tonnisen, Oegstgeest; Jacobus Martinus Van Zanten, Utrecht, all

of Netherlands [73] Assignee: Combinatie Westerschelde v.o.i., Utrecht,

Netherlands [22] Filed: July 28, 1970 21 Appl. No.: 58,775

[30] Foreign Application Priority Data Mar. 31, 1970 Netherlands ..7004556 [52] U.S.Cl ..-.....6l/43,61/46,61/S0 [51 rm. Cl ..E02d 29/00, E01 g 3/00 58 Field of Search ..e1/5o, 46, 43, 42, 63, 52

[ 56] References Cited UNITED STATES PATENTS 3,195,314 7/1965 Degen ..61/5O 26a 24 2724 gab 51 May 30, 1972 Primary ExaminerJacob Shapiro Attorney-Snyder and Butrum [57] ABSTRACT In a known method of filling a space under a structural element with sand, sand and water are supplied into said space through a suspension conduit communicating with a suction dredging installation, rolling on and guided by said structural element, extending above the water level and sucking sand from barges. This suction dredging installation obstructs the shipping and cannot be used at bad weather conditions and/or great depth. For avoiding the above disadvantages the invention provides a method in which the suspension is supplied through a suspension conduit fixed to the structural element, and extending from a junction side of said structural element.

9 Claims, 3 Drawing Figures METHOD OF FILLING A SPACE UNDER A STRUCTURAL ELEMENT AND STRUCTURE THEREFOR The invention relates to a method of laying a foundation for a structural element under water, in which the structural element is supported on a provisional support and a space under the structural element is filled up with foundation material by supplying into the space a suspension of foundation material with water, said structural element being connected with a junction side to another structural element.

Such a method is known and is particularly applied for laying a foundation of a tunnel element or a caisson.

In this method the suspension is supplied into said space from a side of said structural element through a suspension conduit communicating with a suction dredging installation, rolling on and guided by said structural element, extending above the water level and sucking sand from barges. This suction dredging installation and said barges obstruct the shipping during a period of weeks when carrying out this method. This rolling suction dredging installation cannot be used at bad weather conditions and/or at great depth of said structural element. f

The invention hasthe object to provide a method of above mentioned kind which does not obstruct shipping above the structural element and which is applicable in bad weather conditions and at great depth. To this aim the suspension is supplied through a suspension conduit fixed to said first mentioned structural element, said suspension conduit extending from a junction side of said first mentioned structural element.

Further the invention has the object to provide a structural element particularly adapted for laying a foundation thereunder by applying the method according to the invention. This structural element comprising provisional support means for supporting said structural element on a bed so that a space between said bed and said structural element is formed, is characterized by at least one injection pipe communicating with a suspension conduit and extending under the bottom of said structural element for extending into said space, said suspension conduit extending from a junction side of said structural element, said junction side being adapted for connection with an other structural element.

The invention will be illucidated in the following description with reference to the accompanied drawing.

In the drawing show schematically:

FIG. 1 an elevation of a tunnel during performance of the method according to the invention,

FIG. 2 on larger scale a section along the line II-II of FIG. 1, and

FIG. 3 a detail in longitudinal section along the line III-Ill of FIG. 2.

Under a river bed 1 a sink trench 2 having a trench bottom 3 is dredged. In this sink trench 2 tunnel elements 4a-4e are connected with open ramp elements 5. In FIG. 1 tunnel element 4a is already laid and sand is already injected under it. The tunnel element 4b is already sunk, is adjusted on provisional supports 6, its junction side 36 being already connected to the tunnel element 4a. Sand is conveyed in a barge 7 and is sucked up from the barge 7 by means of a floating suction dredger installation 8, positioned outside of the navigation channel, said sand being supplied through pressure conduit 9, suspension conduits l and being injected by injection pipes 11, connected to said suspension conduits 10 into space 35 positioned under the tunnel element 4b. Meanwhile an output of water is sucked up from the space 35 positioned under tunnel element 4b by means of water suction nozzles 12, water suction conduits 13 connected thereto, a pump 14 and a water pressure conduit 15, said output of water being substantially equal to the output of supplied suspension. The tunnel elements 4c, 4d and 4e are not yet sunk in FIG. 1.

It may be seen from vessels 16 that the method according to the invention does not obstruct shipping above the tunnel elements 4);, 4c and 4d.

Each injection pipe 11 is mounted swingably in sealing bearings 17 at a spout distance a from the side of tunnel element 4 in the tunnel bottom 18 and communicates through a valve 19 with a suspension conduit 10b running the entire length of the tunnel-element 4b. This suspension conduit 10b has at each of both ends of tunnel element 411 a coupling member 20b provided with a valve 22 and adapted to be connected by means of a flexible conduit 21 to coupling members 20a and 20c of the tunnel elements 40 and 4c. The workers which have to couple said coupling members come through manholes 23 provided in partitions 24.

Water suction nozzles 12 for sucking up water positioned in the vicinity of the injection pipe 11 communicate through valves 25 with suction conduits 13 provided with coupling members 26b at each of both ends for connection through valves 28 with flexible conduits 27. Inspection glass 29 is provided for determining whether pure water or water with sand is sucked up. As soon as sand is observed in the inspection glass 29 the injection pipe 11 is shifted with the aid of turn wheel 30 or suspension is supplied through a next injection pipe 11 while water is sucked up through a belonging water suction nozzle 12. After use the injection pipes 11 and water suction nozzles 12 are filled up with water tight curing mortar through mortar injection pipes 31.

After finishing the method according to the invention with all tunnel elements 4a-4e to be sunk, the suspension conduits 10 and water suction conduits 13 are cut off under the valves 19 and 25 and are removed.

The provisional supports 6 consist of foot plates 34 and adjustable legs 33 standing on said foot plates 34 and extending through the tunnel bottom 18, the tunnel element 412 supporting on said legs 33 through jacks 32.

- What we claim is:

1. A method of laying a foundation for a structural element under water, in which the structural element is supported on a provisional support and a space under the structural element is filled up with foundation material by supplying into the space a suspension of foundation material with water, said structural element being connected with a junction side to another structural element, characterized in that the suspension is supplied through a suspension conduit fixed to said first mentioned structural element, said suspension conduit extending from a junction side of said first mentioned structural element, the foundation material being supplied into said space by means of at least one injection pipe and water is sucked out of said space by means of at least one water suction nozzle provided in the vicinity of said injection pipe.

2. A method as claimed in claim 1, characterized in that the foundation material is supplied into said space through a plurality of injection pipes fixed to said first mentioned structural element and divided over the surface of its bottom and water is sucked from said space through suction nozzles provided in the vicinity of said injection pipes.

3. A method of laying a tunnel or the like beneath a navigation channel without blocking or impeding traffic through the channel, which comprises the steps of:

a. temporarily supporting a tunnel section below water in a direction across the channel and in spaced relation above the channel bottom to one side of the channel while maintaining the interior of the section in communication with ambient atmosphere through the shore-side end thereof; establishing a flow path for a suspension of foundation material in water from the water surface above said section and downwardly through said shore side end thereof; c. delivering said suspension through said flow path and outwardly through said section to fill the space beneath said section; and simultaneously with (c) pumping water from said space and discharging it through said section and said shoreside end thereof.

4. The method according to claim 3 including the steps of:

e. joining a further section in end-to-end relation to the first section while temporarily supporting such further section in spaced relation to the channel bottom;

f. extending said flow path within said further section;

g. delivering said suspension through said extended flow path and outwardly through said further section to fill the space beneath said further section; and

h. simultaneously with (g), pumping water from said space beneath said further section and discharging it through said further and first sections and said shore-side end of the first section.

5. Structural element comprising provisional support means for supporting said structural element on a bed so that a space between said bed and said structural element is formed, characterized by at least one injection pipe communicating with a suspension conduit and extending under the bottom of said structural element for extending into said space, said suspension conduit extending from a junction side of said structural element, said junction side being adapted for connection with another structural element, and at least one water suction nozzle provided in the vicinity of said injection pipe.

6. Structural element as claimed in claim 5, characterized in that said injection pipe is mounted for swinging movement about a pivot under said structural element, said pivot being arranged at spout distance from a side of said structural element.

7. Structural element as claimed in claim 5, characterized in that a plurality of injection pipes is spaced at spout distances from each other.

8. Structural element as claimed in claim 5, characterized by a suspension conduit having a connection member at each of both ends of said structural element.

9. Structural element as claimed in claim 5, characterized by a valve for shutting off said injection pipe and by a valve for shutting off a water suction nozzle provided in the vicinity of said injection pipe. 

1. A method of laying a foundation for a structural element under water, in which the structural element is supported on a provisional support and a space under the structural element is filled up with foundation material by supplying into the space a suspension of foundation material with water, said structural element being connected with a junction side to another structural element, characterized in that the suspension is supplied through a suspension conduit fixed to said first mentioned structural element, said suspension conduit extending from a junction side of said first mentioned structural element, the foundation material being supplied inTo said space by means of at least one injection pipe and water is sucked out of said space by means of at least one water suction nozzle provided in the vicinity of said injection pipe.
 2. A method as claimed in claim 1, characterized in that the foundation material is supplied into said space through a plurality of injection pipes fixed to said first mentioned structural element and divided over the surface of its bottom and water is sucked from said space through suction nozzles provided in the vicinity of said injection pipes.
 3. A method of laying a tunnel or the like beneath a navigation channel without blocking or impeding traffic through the channel, which comprises the steps of: a. temporarily supporting a tunnel section below water in a direction across the channel and in spaced relation above the channel bottom to one side of the channel while maintaining the interior of the section in communication with ambient atmosphere through the shore-side end thereof; b. establishing a flow path for a suspension of foundation material in water from the water surface above said section and downwardly through said shore side end thereof; c. delivering said suspension through said flow path and outwardly through said section to fill the space beneath said section; and d. simultaneously with (c) pumping water from said space and discharging it through said section and said shore-side end thereof.
 4. The method according to claim 3 including the steps of: e. joining a further section in end-to-end relation to the first section while temporarily supporting such further section in spaced relation to the channel bottom; f. extending said flow path within said further section; g. delivering said suspension through said extended flow path and outwardly through said further section to fill the space beneath said further section; and h. simultaneously with (g), pumping water from said space beneath said further section and discharging it through said further and first sections and said shore-side end of the first section.
 5. Structural element comprising provisional support means for supporting said structural element on a bed so that a space between said bed and said structural element is formed, characterized by at least one injection pipe communicating with a suspension conduit and extending under the bottom of said structural element for extending into said space, said suspension conduit extending from a junction side of said structural element, said junction side being adapted for connection with another structural element, and at least one water suction nozzle provided in the vicinity of said injection pipe.
 6. Structural element as claimed in claim 5, characterized in that said injection pipe is mounted for swinging movement about a pivot under said structural element, said pivot being arranged at spout distance from a side of said structural element.
 7. Structural element as claimed in claim 5, characterized in that a plurality of injection pipes is spaced at spout distances from each other.
 8. Structural element as claimed in claim 5, characterized by a suspension conduit having a connection member at each of both ends of said structural element.
 9. Structural element as claimed in claim 5, characterized by a valve for shutting off said injection pipe and by a valve for shutting off a water suction nozzle provided in the vicinity of said injection pipe. 